ASK ANY birdwatcher of a certain age to name the book that inspired them to first pick up binoculars and one title will come to mind.

The Observer’s Book Of Birds was small enough to fit into an inside jacket pocket but has always stood as a giant on the bookshelf.

Any schoolchild browsing the delectable plates of golden oriole, red-backed shrike or hobby could not wait to go out and look for these wonders of the countryside.

I remember longing to see both the longeared and short-eared owls, so lovingly drawn by Archibald Thorburn they looked ready to fly off the page.

My first of many copies came on my fifth birthday, too young to go off birdwatching alone but not too young to learn my birds.

Dad would test me every night before bedtime, covering the text and making me identify each picture.

Since first appearing in 1937, the Observer’s Book Of Birds has been surpassed by skeins of fi eld guides for birders, each new title reflecting our increased knowledge and understanding but, all too often, with increasingly esoteric language. Of late, I have longed for a book to give my grandson for his forthcoming fifth birthday that will not only encourage him to look at birds but will become indispensible for years to come.

Then I had that eureka moment when I opened the new Collins BTO Guide To British Birds.

Here is the guide for the 21st century, a title to ensure that anyone with a passing interest in birds has all the vital information they need to become a fully-fledged birder.

The book covers “Every common British bird – every plumage” and as we browse through its 320 pages, it keeps to its word.

Authors Paul Sterry and Paul Stancliffe have used fantastic bird photography to provide a comprehensive coverage of all our regularly recorded species.

The book has more than1,200 photographs covering the 250 species that nest, winter or pass through the UK regularly during migration.

Individual species are given their own page, with photographs of the posture in which they are normally encountered with flight angles for the more aerial species.

Picking two of my favourites, long-eared and short-eared owls, we are given a masterclass in these often confused birds’ field identification, with annotated photographs of the diagnostic wing patterning, plus up-to-date information on status, habit preferences and behaviour.

Where this guide enters a new dimension is by harnessing the BTO’s incredible data base to provide the birdwatcher with an accurate insight into where and when to see a species.

Each bird’s map is colour coded to depict its seasonal presence and also its abundance.

What will excite birdwatchers are the “calendar wheels” showing months when birds can be seen and the likely chances of encountering them, based on records provided to the BTO’s BirdTrack resource.

For instance, if we look at notoriously elusive species such as the “eared owls”, a birder has to be extremely lucky to get a sighting, with figures of four and five per cent for the long-eared and short-eared, respectively.

We have copies of the Collins BTO Guide To British Birds (£19.99) to give to the first five readers who can answer the following question: What bird appears on the book’s front cover?

Send answers on a postcard to Birdman, Sunday Express, 10 Lower Thames Street, London EC3R 6EN, by July 3.